Dental resins are photopolymers developed for dental laboratories and practices and printed mainly by SLA and DLP; some grades are also validated on masked-LCD (MSLA) printers. They fall into two groups. Model resins produce accurate study, working and thermoforming models, dies and gingiva masks, and are not intended for use in the mouth. Biocompatible grades are certified for specific devices, such as surgical guides, occlusal splints and night guards, indirect bonding trays, denture bases, and temporary crowns and bridges.
Biocompatibility is not a property of the liquid resin alone. A printed device is only as safe as its whole workflow: the certified resin, a printer validated for it, the specified washing, drying and post-cure, and the cleaning or sterilization stated in the instructions for use. Regulatory responsibility for the finished device stays with the customer who places it on the market or uses it, typically a dental laboratory or practice. Choose dental resin when you need accurate dental models or patient-specific appliances made within such a workflow; for parts outside dentistry, standard or engineering resins are usually the better fit.
Mechanical and physical properties
| Property | Typical value | Notes |
|---|---|---|
| Flexural strength (rigid grades) | ≈ 70–150 MPa | Model, guide and temporary-restoration grades; ceramic-filled crown resins at the upper end. |
| Flexural modulus (rigid grades) | ≈ 2.0–4.5 GPa | Ceramic-filled restorative grades are the stiffest. |
| Splint grades | Rigid or flexible | Rigid grades resemble PMMA splints; flexible grades are more comfortable and easier to seat. |
| Layer thickness | ≈ 50–100 µm | 50 µm is common for appliances and restorations, 100 µm for many models. |
| Heat resistance of model grades | Grade-dependent | Models for thermoforming must withstand the heated sheet; choose a grade rated for it. |
| Water sorption and solubility | Tested for restorative and base polymers | Limits come from the standard named in the instructions for use, such as ISO 4049, ISO 10477 or ISO 20795. |
| Biological evaluation | ISO 10993-1 and ISO 7405 | Applies to the certified grade processed exactly as specified; model resins are usually not evaluated for use in the mouth. |
| Contact duration category | Limited, prolonged or long-term | ISO 10993-1 categories: up to 24 hours, up to 30 days, or longer; each grade is evaluated for a stated use. |
| Sterilization or disinfection | Grade-dependent | Surgical guide grades are usually designed for steam sterilization; follow the cycle in the instructions for use. |
| Shade and translucency | Model colors, clear, tooth shades | Restorative grades come in common tooth shades such as A1 to A3; clear grades serve splints and guides. |
Typical ranges across common dental grades, measured on printed and fully post-cured specimens to ISO 178, ISO 4049, ISO 10477 or ISO 20795, depending on the grade. Each certified resin has its own instructions for use, validated printers and processing parameters, and only that combination supports its biocompatibility claims. Use the datasheet and instructions for use of the grade named in your quote.
Printing dental parts with SLA and DLP
Dental parts are usually printed on SLA or DLP machines in validated combinations of printer, resin and settings. For biocompatible grades, every step after printing is part of the validated process: washing in the specified solvent for the specified time, complete drying, post-cure in a curing unit with the specified wavelength, temperature and duration, then support removal and finishing. A deviation, such as an under-cured part, can leave residual monomer and compromise biocompatibility. Design and ordering points:
- Validated combinations: state the resin and printer combination your workflow requires, and note in the order that biocompatible grades must not be substituted without your approval.
- Models: hollow models with drainage openings save resin; keep bases and labels away from teeth and margins. For thermoforming, specify a model grade rated for the forming heat.
- Surgical guides: orient so supports stay off the tissue-contact surface and the sleeve holes; size sleeve holes with the offset from your sleeve and planning software, and check the sleeve fit after post-cure.
- Splints and night guards: keep supports off the fitting surface and place them on outer faces that will be polished; state the minimum thickness of your design.
- Temporary crowns and bridges: print in the orientation specified for the grade, keep supports off margins and occlusal contacts, and respect the minimum wall thickness and connector size from the instructions for use.
- Data: export from your dental CAD software in millimeters, one file per unit or arch, with file names that identify the case but contain no patient data.
Tolerances and surface
Without a tolerance on the drawing, Uretyco's default for SLA parts is ±0.2 mm or ±0.2%, whichever is greater. Dental fit depends less on a single dimension than on calibration, orientation and post-cure shrinkage, so check the fit of guides, splints and restorations on the model before use, as your clinical workflow requires. Printed surfaces are smooth; appliances worn in the mouth are polished on their outer surfaces to reduce plaque build-up, while fitting surfaces stay as printed.
Finishing options
For intraoral appliances, finishing is part of the validated workflow. Use only materials and methods approved in the instructions for use of the resin.
| Finish | Effect | Notes |
|---|---|---|
| Support removal and spot grinding | Clean contours | Low speed and light pressure avoid heat and cracks in thin guides. |
| Polishing | Smooth, glossy outer surfaces | Standard for splints and temporaries; fitting surfaces are not polished. |
| Light-cure glaze and stains | Natural look, sealed surface | Only with products approved for the resin; common on temporary crowns. |
| Model trimming and labeling | Ready-to-use models | Bases are trimmed and case labels added as specified. |
A biocompatible resin yields a biocompatible device only when it is printed, washed, post-cured and finished exactly as its instructions for use specify. Glazes, adhesives and repair materials must be approved for the same use. Cleaning, disinfection or sterilization before use remains the responsibility of the user, following the instructions for use.
Cost and lead-time drivers
Certified dental resins cost considerably more per liter than standard resin, but dental parts are small and usually printed in batches:
- Batching: many models, guides or crowns share one build, especially on DLP, so the cost per unit falls as the batch grows.
- Model volume: solid models use far more resin than hollow ones; hollow models with drainage openings lower the cost.
- Validated processing: the specified washing, post-cure and handling steps take time and cannot be shortened.
- Manual finishing: polishing splints and glazing temporaries are manual steps that often cost more than the material.
- Review and documents: orders that state an intraoral or other regulated use may be reviewed by an engineer before acceptance, and documents such as a Certificate of Conformity or a measurement report are optional and must be requested at quote time.
Dental resin vs. other options
| Option | Typical dental use | Strengths | Limitations |
|---|---|---|---|
| Dental resin (SLA, DLP) | Models, guides, splints, temporaries | Fast, many units per build, fine detail | Workflow must stay validated; lower strength than milled materials |
| Standard resin (SLA, DLP, MSLA) | Study and presentation models | Low cost, smooth surface | Not for use in the mouth |
| Milled PMMA (CNC) | Temporaries, splints, denture bases | Dense, industrially polymerized material; high strength; polishes well | Material waste and tool wear; slower for large batches |
| Thermoformed sheet | Splints, aligners, retainers | Low material cost per appliance | Needs a printed model; the sheet thins over curved areas |
| Cobalt chrome (cast or printed) | Frameworks and metal substructures | High strength in thin sections | Metal route; casting or DMLS |
Printed dental resin suits batches of models and patient-specific appliances. Milled PMMA remains the choice when maximum strength and long-term stability of temporaries or splints matter, thermoforming is economical for aligners and simple splints made on printed models, and cobalt chrome covers metal frameworks.
When not to choose dental resin
Intraoral use without the certified grade, a validated printer and the specified post-processing: the device may not be biocompatible. Model resins in the mouth: they are not intended for it. Definitive restorations from temporary grades: wear time is limited to what the instructions for use allow. Non-dental parts that only need a smooth surface: standard or engineering resins cost less. Projects without the documentation your regulatory process requires: state those requirements at quote time; if a required document cannot be provided, this is clarified before order confirmation.
Typical applications
- Study, working and orthodontic models, dies and gingiva masks.
- Thermoforming models for aligners, retainers and splints.
- Surgical guides for implant placement.
- Occlusal splints, night guards and indirect bonding trays.
- Temporary crowns and bridges, and try-in restorations.
- Denture bases and try-in dentures in grades certified for that use.
Specifying dental resin on Uretyco
- 1Upload STL or 3MF
Export from your dental CAD software in millimeters, one file per unit or arch, with file names that identify the case but contain no patient data.
- 2State the application and grade
Say whether the part is a model, guide, splint or temporary restoration, and name the certified resin and printer combination your workflow is validated for.
- 3State the intended use
Note intraoral use, contact duration and any sterilization; regulated uses may be reviewed manually before an order is accepted.
- 4Mark fitting surfaces and critical features
Mark fitting surfaces, sleeve holes and margins that must stay free of supports, and add notes for sleeves or labels.
- 5Choose finishing and documents
Specify polishing, glazing or model trimming, and request optional documents, such as a Certificate of Conformity or a measurement report, at quote time.
- 6Review the quote
Check the confirmed resin, technology, finishing and lead time; certified grades and validated workflows are confirmed during quote and order review.
FAQ
Is every dental resin biocompatible?
No. Model resins are made for models used outside the mouth. Biocompatible grades are evaluated for specific uses and contact durations, and those claims hold only when the resin is processed on a validated printer with the specified washing, post-cure and finishing. Check the instructions for use of the exact grade.
Who is responsible for regulatory compliance?
The legal manufacturer of the finished device, usually the dental laboratory or practice that makes it for a specific patient. In the EU, patient-specific appliances are often handled as custom-made devices under the Medical Device Regulation (EU) 2017/745, and Türkiye applies a regulation harmonized with it. Uretyco produces parts to your files and specification; the regulatory obligations for the finished device stay with you, so state your requirements and intended use at quote time.
Can dental resins be printed on MSLA printers?
Some can. Several certified grades are validated for specific masked-LCD printers, but the validation covers only the listed printers and settings. For biocompatible parts, the printer must be on the validated list of the resin; for models, the choice between SLA, DLP and MSLA can be left to the quote.
Can printed models be used to thermoform aligners and splints?
Yes, with a model grade rated for thermoforming, because the heated sheet can deform models made from resins with low heat resistance. Hollow models need enough wall thickness so they do not collapse under the forming pressure.
Related resources
- Castable ResinBurnout patterns for cast crowns and frameworks.
- Standard SLA ResinLow-cost study and presentation models.
- PolyJet BiocompatibleBiocompatible grades for PolyJet printing.
- Cobalt ChromeCast or printed alloy for dental frameworks.
- PMMA (Acrylic)Machined acrylic parts and their properties.
- Certificates & Inspection ReportsOptional documents requested at quote time.
Related materials
Plastics
Standard SLA
General-purpose photopolymer for SLA and DLP printing: the smoothest surfaces and finest detail of any common 3D printing process, but brittle and heat-sensitive. The default for cosmetic prototypes, detailed models and casting masters.
Plastics
Castable Resin
Photopolymer that burns out cleanly in the investment casting flask, so a printed pattern replaces a wax model. For jewelry, dental frameworks and small precision castings in gold, silver, bronze and cobalt chrome; patterns need a resin burnout schedule.
Plastics
Clear Resin
Unpigmented photopolymer for SLA, DLP and MSLA that prints translucent and becomes close to transparent after sanding and polishing or a clear coat. For see-through prototypes, fluidic models and light covers; brittle and prone to yellowing.
Plastics
High-Temp Resin
Heat-resistant photopolymer for SLA and DLP printing, reaching an HDT of roughly 100–250 °C or more after thermal post-cure. Used for low-volume mold inserts, heat-exposed fixtures and hot air or fluid flow tests; stiff but brittle.
Plastics
Tough Resin
Engineering photopolymers formulated to behave like ABS or polypropylene: far more impact- and fatigue-tolerant than standard resin, with the same smooth surface and fine detail. For snap-fits, enclosures, jigs and functional prototypes at room temperature.
Elastomers
Flexible Resin
Soft, rubber-like photopolymers from about Shore 50A to 80A that bend, stretch and spring back. For soft-touch prototypes, small seals, grips and fine elastic details; less tear- and abrasion-resistant than TPU or silicone.
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